Middle East peace summit negotiators broke into groups Friday in a bid to bridge wide gaps, amid a report from Gaza City that the Palestinians threatened to quit over perceived Israeli bias in a US document, reported AFP.

In Gaza City, a senior Palestinian source said Washington had withdrawn the written document presented at Camp David after Yasser Arafat threatened to quit.

"The Palestinian side threatened to walk out after receiving a document from US Middle East envoy Dennis Ross covering all the issues of borders, Jerusalem and refugees, protesting that it adopted the Israeli positions," the source told AFP.

"The talks almost collapsed," he added.

"President Bill Clinton himself intervened and withdrew the paper when he returned to the summit on Thursday and negotiations resumed."

At the Camp David press center in Thurmont, Maryland, White House spokesman Joe Lockhart declined to comment, reported Reuters.

"Commenting on that would break the basic tenets of the news blackout," he told a briefing. But he added, "I didn't see any bags today."

Sources close to the talks said it had been the US intention to present specific bridging proposals Thursday, said Reuters.

Lockhart refused to be drawn on the proposals, saying only: "I certainly would not eliminate any diplomatic initiative or effort that might help push the process forward.

"But I'm not going to discuss any of those efforts or any of those options."

An Israeli official said the United States had not submitted any proposed compromises in writing but that Clinton "did float some ideas."

The story was leaked by a direct call from the Camp David summit to Palestinian officials in Gaza City, said Reuters.

Lockhart disclosed a change in the talks saying, "They have divided up into smaller groups and will be dealing directly on the core issues."

"These are intractable issues," he said, referring to the future of Jerusalem, borders of a Palestinian state, the fate of 3.7 million Palestinian refugees, Jewish settlements in Israeli-occupied territories and security guarantees for Israel, said Reuters.

"This is very serious at times discussions are tense," Lockhart added.

He refused to reveal anything he deemed related to the "substance" of the talks, citing the blackout.

Clinton met Barak and Arafat separately on Friday again after bilateral talks with them on Thursday night, Lockhart said.

But other than at evening meals, the three leaders have not met together since the talks opened on Tuesday while Barak and Arafat have met together only once since then, according to US officials, quoted by AFP.

The negotiations were due to ease off Saturday, the Jewish sabbath.

ALBRIGHT MEETS WITH PALESTINIAN LEADERS

As Clinton, who is expected to remain at the summit through the weekend, met with his advisors on Friday, Secretary of State Madeleine Albright went to see several Palestinian leaders who want to visit Camp David to speak with Arafat, AFP added.

Albright met the Palestinians in Emmitsburg, 12 kilometers north of Camp David.

The United States has been cool to the Palestinians' demand to see Arafat at Camp David, citing agreed restrictions barring comings and goings from the heavily guarded facility, said AFP.

The Palestinians have accused the United States of keeping Arafat in talks with the Israelis without contact with his supporters in a bid to pressure him into concessions.

"This is not the best form of negotiation, to isolate President Arafat from the executive committee and his constituency," Hanan Ashrawi, one of the Palestinian spokespeople, said after the Albright meeting.

"We are not a negotiating team but we are coming here to represent a wide spectrum of parties," she said, allowing, however that Albright gave no commitment they would be allowed into Camp David.

Lockhart maintained that if Arafat wanted to, he "certainly can meet with them if he wants," raising questions about whether the Palestinian leader really wants to see the officials, AFP said.

Lockhart insisted Washington had never received a formal request for the officials to visit Arafat and repeated twice more that the Palestinian president would be allowed to see them if he "wanted to," implying that he would have to leave Camp David to do so, said AFP - (Several Sources)